This invention relates generally to disposable hypodermic syringes and more particularly to a novel hypodermic syringe having a needle assembly which is automatically retracted within a tubular housing after the syringe has been used to inject the fluid within a patient.
A growing concern within the health care field is the exposure of health care workers such as doctors and nurses to dangerous diseases such as hepatitis and acquired immuno deficiency syndrome (AIDS) transmitted by way of accidental needle sticks from contaminated used needles.
Accidental needle sticks often occur after use when a worker attempts to recap the used contaminated needle and accidentally sticks himself, or when a used needle is left on a work surface where other workers may accidentally stick themselves. Various proposals have been offered in the past for recapping, shielding or retracting used needles to prevent accidental sticks. Typical proposals are illustrated in prior U.S. Pat. Nos. 3,306,290, 4,026,287, 4,592,744, 4,747,829, 4,747,831, and 4,767,413. While the myriad of proposals exemplified by the designs illustrated in these prior patents serve to accentuate the dangers of exposure to diseases and the concerns of the medical industry none of the prior proposals has totally eliminated the dangers nor has any been widely accepted for use.
Also of concern among health officials is the spread of disease caused by the common practice among drug addicts of reusing or sharing used needles.